The use of surgically implanted mechanical heart valves has become widespread throughout the world and even routine in many countries. There are a variety of mechanical heart valves that have become well-accepted for use in the United States, Europe and Japan as well as in other countries throughout the world, one of which is sold as the On-X heart valve by Medical Carbon Research Institute, LLC, the assignee of this application. This mechanical heart valve prosthesis is shown in U.S. Pat. Nos. 5,545,216, 5,641,324, 5,772,694 and 5,908,452, for example.
Special tools have been developed to assist in the implantation of mechanical heart valves of this general type. It is important that an effective tool should be capable of holding the valve and facilitating its manipulation at the implantation site in order to properly position it.
Shown in FIG. 1 is a prior art valve holder 2 of the type often used for implanting a mechanical heart valve in 1992 and earlier. The valve holder 2 consists of two parts which are generally symmetrical to one another, a first or front part 4 and a second or back part 6. The prior art valve holder 2 is illustrated in FIG. 1 in an open condition. The two main body parts of the holder are hinged in some fashion, as example, by a pin 7 or by a living hinge. Two legs 8 and 10 are configured to press outward against an inside wall of an annular valve body when front and rear upper shaft sections 12, 14, respectively, are held together, which is often accomplished by a knotting a flexible tie. The front upper section 2 also has a longitudinal slot 18 which aids in cutting the tie, and it may have a transverse bore through which the tie is threaded and knotted so it remains associated with the inserter and is removed with it following implantation. The distal end of a handle (not shown) is usually received in a cavity or receptacle 19 formed in a cap portion 20 that surmounts the front part 12 of the holder, and the handle is secured in a conventional manner.
Reference is also made to the above-described inserter in U.S. Pat. No. 5,236,540 entitled “Heart Valve Holder-Rotator”. This patent illustrates and describes a similar inserter where the main body of the holder is formed with a pair of opposed hinged side sections which have depending legs that move toward and away from each other in a manner similar to the two hinged parts described above, but both legs pivot with respect to a central portion of the body. Another heart valve holder of this general type is shown in U.S. Pat. No. 5,443,502.
Whereas these heart valve holders do securely engage a heart valve prosthesis so as to allow it to be positioned and rotated, oftentimes it is difficult to facilitate the passage of the leading end of the heart valve prosthesis through the annulus in the heart of the patient where the damaged natural valve leaflets were excised. It has been found that this may be a particular problem during the aortic valve replacement when the surgeon must work through the immediately upstream portion of the aorta. Accordingly, improvements in these tools for handling and implanting heart valves have been sought.